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Microlink function:
 How to compress

Kiko Beats
@kikobeats

September 3, 2022 ()

The query parameter function allows you dynamic code execution with remote headless browser access on runtime:

The following examples show how to use the Microlink API with CLI, cURL, JavaScript, Python, Ruby, PHP & Golang, targeting 'https://microlink.io' URL with 'function', 'meta' & 'scripts' API parameters:

CLI Microlink API example

microlink https://microlink.io&function='({ page }) => page.evaluate("jQuery.fn.jquery")'&scripts=https://code.jquery.com/jquery-3.5.0.min.js

cURL Microlink API example

curl -G "https://api.microlink.io" \
  -d "url=https://microlink.io" \
  -d "function=(%7B%20page%20%7D)%20%3D%3E%20page.evaluate(%22jQuery.fn.jquery%22)" \
  -d "meta=false" \
  -d "scripts=https://code.jquery.com/jquery-3.5.0.min.js"

JavaScript Microlink API example

import mql from '@microlink/mql'

const { data } = await mql('https://microlink.io', {
  function: '({ page }) => page.evaluate("jQuery.fn.jquery")',
  meta: false,
  scripts: [
    "https://code.jquery.com/jquery-3.5.0.min.js"
  ]
})

Python Microlink API example

import requests

url = "https://api.microlink.io/"

querystring = {
    "url": "https://microlink.io",
    "function": '''({ page }) => page.evaluate("jQuery.fn.jquery")''',
    "meta": "false",
    "scripts": "https://code.jquery.com/jquery-3.5.0.min.js"
}

response = requests.get(url, params=querystring)

print(response.json())

Ruby Microlink API example

require 'uri'
require 'net/http'

base_url = "https://api.microlink.io/"

params = {
  url: "https://microlink.io",
  function: '({ page }) => page.evaluate("jQuery.fn.jquery")',
  meta: "false",
  scripts: "https://code.jquery.com/jquery-3.5.0.min.js"
}

uri = URI(base_url)
uri.query = URI.encode_www_form(params)

http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true

request = Net::HTTP::Get.new(uri)
response = http.request(request)

puts response.body

PHP Microlink API example

<?php

$baseUrl = "https://api.microlink.io/";

$params = [
    "url" => "https://microlink.io",
    "function" => '({ page }) => page.evaluate("jQuery.fn.jquery")',
    "meta" => "false",
    "scripts" => "https://code.jquery.com/jquery-3.5.0.min.js"
];

$query = http_build_query($params);
$url = $baseUrl . '?' . $query;

$curl = curl_init();

curl_setopt_array($curl, [
    CURLOPT_URL => $url,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_ENCODING => "",
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_TIMEOUT => 30,
    CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
    CURLOPT_CUSTOMREQUEST => "GET"
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
    echo "cURL Error #: " . $err;
} else {
    echo $response;
}

Golang Microlink API example

package main

import (
    "fmt"
    "net/http"
    "net/url"
    "io"
)

func main() {
    baseURL := "https://api.microlink.io"

    u, err := url.Parse(baseURL)
    if err != nil {
        panic(err)
    }
    fn := `({ page }) => page.evaluate("jQuery.fn.jquery")`

    q := u.Query()
    q.Set("url", "https://microlink.io")
    q.Set("function", fn)
    q.Set("meta", "false")
    q.Set("scripts", "https://code.jquery.com/jquery-3.5.0.min.js")
    u.RawQuery = q.Encode()

    req, err := http.NewRequest("GET", u.String(), nil)
    if err != nil {
        panic(err)
    }

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
        panic(err)
    }
    defer resp.Body.Close()

    body, err := io.ReadAll(resp.Body)
    if err != nil {
        panic(err)
    }

    fmt.Println(string(body))
}
The function body can be pass in plain text, but also multiple compression algorithms are supported.

Brotli

brotli
 is a modern and general purpose compression algorithm with a well compression ratio.
const mql = require('@microlink/mql')
const { promisify } = require('util')
const zlib = require('zlib')

const brotli = promisify(zlib.brotliCompress)

const toBrotli = async code => {
  const buffer = await brotli(code)
  return buffer.toString('base64url')
}

const code = '({ page }) => page.evaluate("jQuery.fn.jquery")'

const { status, data } = await mql('https://microlink.io', {
  function: `br#${await toBrotli(code)}`,
  meta: false,
  scripts: 'https://code.jquery.com/jquery-3.5.0.min.js'
})

mql.render(data.function)
brotli has a good compression ratio & speed.

Lz-string

lz-string
 is designed to be efficient for compressing text.
const { compressToURI } = require('lz-ts')
const mql = require('@microlink/mql')

const code = compressToURI('({ page }) => page.evaluate("jQuery.fn.jquery")')

const { status, data } = await mql('https://microlink.io', {
  function: `lz#${code}`,
  meta: false,
  scripts: 'https://code.jquery.com/jquery-3.5.0.min.js'
})

mql.render(data.function)
lz-string is lightweight enough to be used for client-side apps.

Gzip

gzip is the predecessor of brotli and it's widely supported.
const mql = require('@microlink/mql')
const { promisify } = require('util')
const zlib = require('zlib')

const gzip = promisify(zlib.gzip)

const toGzip = async code => {
  const buffer = await gzip(code)
  return buffer.toString('base64url')
}

const code = '({ page }) => page.evaluate("jQuery.fn.jquery")'

const { status, data } = await mql('https://microlink.io', {
  function: `gz#${await toGzip(code)}`,
  meta: false,
  scripts: 'https://code.jquery.com/jquery-3.5.0.min.js'
})

mql.render(data.function)
It's possible to compress using gzip directly in the browser, using
Compression Streams API
.

Join the community

All of these improvements or features are community driven: We listen to your feedback and act accordingly.
Whether you are building a product, an indie developer, or just interested in web technologies, come chat with us.